diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3f90ec9dacee..17de0b1c4d69 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4528,6 +4528,8 @@ static inline void hrtick_update(struct rq *rq) } #endif +static bool cpu_overutilized(int cpu); + /* * The enqueue_task method is called before nr_running is * increased. Here we update the fair scheduling stats and @@ -4538,6 +4540,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; + int task_new = !(flags & ENQUEUE_WAKEUP); /* * If in_iowait is set, the code below may not trigger any cpufreq @@ -4577,9 +4580,12 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) update_cfs_shares(cfs_rq); } - if (!se) + if (!se) { add_nr_running(rq, 1); - + if (!task_new && !rq->rd->overutilized && + cpu_overutilized(rq->cpu)) + rq->rd->overutilized = true; + } hrtick_update(rq); } @@ -7333,11 +7339,12 @@ group_type group_classify(struct sched_group *group, * @local_group: Does group contain this_cpu. * @sgs: variable to hold the statistics for this group. * @overload: Indicate more than one runnable task for any CPU. + * @overutilized: Indicate overutilization for any CPU. */ static inline void update_sg_lb_stats(struct lb_env *env, struct sched_group *group, int load_idx, int local_group, struct sg_lb_stats *sgs, - bool *overload) + bool *overload, bool *overutilized) { unsigned long load; int i, nr_running; @@ -7371,6 +7378,9 @@ static inline void update_sg_lb_stats(struct lb_env *env, */ if (!nr_running && idle_cpu(i)) sgs->idle_cpus++; + + if (cpu_overutilized(i)) + *overutilized = true; } /* Adjust by relative CPU capacity of the group */ @@ -7480,7 +7490,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd struct sched_group *sg = env->sd->groups; struct sg_lb_stats tmp_sgs; int load_idx, prefer_sibling = 0; - bool overload = false; + bool overload = false, overutilized = false; if (child && child->flags & SD_PREFER_SIBLING) prefer_sibling = 1; @@ -7502,7 +7512,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd } update_sg_lb_stats(env, sg, load_idx, local_group, sgs, - &overload); + &overload, &overutilized); if (local_group) goto next_group; @@ -7546,8 +7556,14 @@ next_group: /* update overload indicator if we are at root domain */ if (env->dst_rq->rd->overload != overload) env->dst_rq->rd->overload = overload; - } + /* Update over-utilization (tipping point, U >= 0) indicator */ + if (env->dst_rq->rd->overutilized != overutilized) + env->dst_rq->rd->overutilized = overutilized; + } else { + if (!env->dst_rq->rd->overutilized && overutilized) + env->dst_rq->rd->overutilized = true; + } } /** @@ -8921,6 +8937,9 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) if (static_branch_unlikely(&sched_numa_balancing)) task_tick_numa(rq, curr); + + if (!rq->rd->overutilized && cpu_overutilized(task_cpu(curr))) + rq->rd->overutilized = true; } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 92d52b6398ac..690bfb6a89ea 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -557,6 +557,9 @@ struct root_domain { /* Indicate more than one runnable task for any CPU */ bool overload; + /* Indicate one or more cpus over-utilized (tipping point) */ + bool overutilized; + /* * The bit corresponding to a CPU gets set here if such CPU has more * than one runnable -deadline task (as it is below for RT tasks).